47.65% is the change from 170 to 251
Calculation steps:
[( 251 - 170 ) ÷ 170] x 100 = 47.65%
Formula
Percentage change = [(251 - 170) / 170] x 100
Subtract the new number by the original number
251 - 170 = 81
81 ÷ 170 = 0.4764705882352941
0.4764705882352941 x 100 = 47.65%